Some area control valves include a valve spool slidably disposed within a bore of a housing to define a zero leak valve interface between a conical valve face formed on the spool and an annular valve seat formed on the body. One of the problems experienced is that a hydrodynamic pressure field is sometimes formed by a convergent wedge of oil between the conical valve face and the valve seat, particularly where the conical intersects the cylindrical spool. This convergent wedge of oil prevents the conical valve face from fully closing against the arcuate valve seat, particularly when the closing force on the valve spool is small.
Thus, it would be desirable to provide a zero leak valve interface between the valve spool and the valve seat so that a divergent wedge of oil is formed to break up the hydrodynamic field to allow the valve face to fully close against the valve seat.
The present invention is directed to overcoming one or more of the problems as set forth above.